Guiding device for phonograph tone-arms.



J. A. SHQEMAKER. GUIDING DEVICE FOR PHONOGHAPH TONE ARMS.

APPLICATIONC FILED MAY 22, i911.

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entre startte retenir JOHN A'. SH0El'tlIAKIEBI, 0F AIDA, MINNESOTA..

` GUDING DEVICE FOR PHONOGRAEH TGNE-RMS.

Specification of Letters Patent.

)Patented apro 3d, idle..

Application filed May 22, 1917. Serial No. 170,315.

. of the groove or path in the record,` the de- .mon to machines of this type.

vice having particular application to the Edison phonograph where the tone arm is raised and lowered to separate the diamond point trom the record or position it thereon preparatory t the operation of the machine.

The inventionconsists generally in various constructions and combinations, all as hereinater described and particularly pointed out in the claims. i

ln' the accompanying drawings forming part of this specification,

Figure 1 is a plan view oit the top of an Edison phpnograph `with my invention applied thereto,

Fig. 2 is a plan sectional View of the horn arm, with my invention connected there with,

Fig. 3 is adetail/'sectional view, taken on the line 3--3 of Fig. li, showing a portion of the device' mounted on the wall of the cabinet,

Fig. d `is an elevation of the horn arm anda section of the cabinet, showing the relative arrangement of the'path-linding device thereon.

ln the drawing, 2 represents the cabinet of the phonograph, 3 the record turn-table and i the tone arm having the usual sound box 5 and point or needle, not shown. @n one side of the machine is the shaft 6 connected with the arm and a lever 7 for raising or lowering the shaft and operating the arm, which is connected with the shaft under the turn-table in the well known way coni- In connection with the shaft 6 is an automatic stopping device 8 in general use.

Upon the tone arm I provide a clamp 9 having;f a pin l0 thereon projecting hori- 'zmtally toward the casing of the machine.

This clamp is secured by a bolt l1 or by other suitable means and in practice the pin y 'may be formed directly on the arm itself,

if desired. 12 is al plate, having a longitudinal slot 13 therein to receive screws 14; on 'which said plate is slidable horizontally. rThe plate 15 is secured at 1G on the plate l2 and has notches 17 therein to receive a pin 18 mounted in the wall of the casing. These recesses indicate theV different adjustments of the plate 12 for long and short records, that is, twelve or ten inches, the position of the recesses being accurately determined by previous measurement and adjustment.

' The plate l5 is split longitudinally to 4form a spring section 19 having `a downwardly. turned end portion 2O and a section 2l havingl a substantially right angled end portion 22 terininating` in an upwardly inclinedpart The part 22 forms a square shoulder at the end of the' spring 2]. and' projects inwardly across the end part 2O in the path of the pin 10, which is mounted to engage and depress the plate i9. There is sufficient space between the part 22 and the end 20 to allow the pin l() to drop down between them and the tone arni a be depressed -suiiiciently .to engage the diamond point with the l@groove in the record. This space or ga between theparts 22 and 20-is so positione by the adjustment of the plate 12 that when the arm is dropped or lowered by the movement of the lever 7, it will always bring the diamond point or needle at the starting point of the record without any further attention on the part of the-operator. The plate l2 is provided with a slot 12 for the spring 19 and has aA flange #13 to serve as a stop for the pin 10 to prevent backward movement. rift-er the record has been played and the arm is returned to its initial position, the pin l0 will strike the upwardly turned end 23, lifting theplate sufficiently to clear the angle part 22 and then riding over the plate 19 to the starting part of the arm. When a new record has been placed in the machine, it will only be necessary to swing the arnl against the stop 22 when the lever 'l may be operated to drop the arm upon the` record. ln case of a change in. the size of the record to be played, the plate l2 is moved lengthwisel on its supports la, shifting 'from one notch 1T to the other on the pin 18, according to whether the record to be played is largerI or smaller.

In practice, the pin 10 inay be integrally formed on the arm, where the invention is applied to :1 machine when it is built, but for machines already constructed, .l may use the clamp 9, securing it by suitable means, such as the bolt 11.

In various ways the details of construction herein shown and described may be modified and still be within the scope of my invention.

I claim as my invention:

1..'1`he combination with a phonograph turn-table, of a tone arm comprising a horizontal part extending over the turn-table anda downwardly turned part; ext-ending below the table, and a stop so positioned in relation to the downwardly extending part of the tone arm that when the tone arm is raised and in position to be lowered onto the record said stop and a part of said arm will co-act with each other to position the stylus of the arm over the starting point of the record groove, said stop and part of the arm beingout of co-acting relation when the arm is lowered.

2. The combination, with a phonograph turn table, of a tone arm mounted for vertical movement comprising a horiontal part extending over the turn table and a downwardly turned part extending below the turn table, and means adjustably mounted and coperating with said downwardly turned part for guiding said arm to the starting point in the groove of the record.

The combination, with a phonograph turn-table, of an oscillating tone arm, a pin mounted on` said arm and plates in the path of said pin having means for checking the oscillation ofsaid arm but permitting movement thereof toward ythe record.

4. The combination, with a phonograph turn-table and oscillating tone arm, of a pin mounted on said arm, a spring member hav# ing a shoulder in the path of said pin for checking the horizontal movement of said arm at a point above the normal starting position of said arm on a record.

5. The combination, with a phonograph turn-table, ofIl an oscillating tone arm, a spring memberA having a shoulder formed thereon, a pin mounted on said arm to engage said shoulder when said arm is oscillated in one direction7 and said spring member having an inclined surface for contacting with said pin to allow said arm to be moved past said shoulder when it is oscillated in the opposite direction.

G. A device for positioning a phonograph tone arm comprising a plate having spring members thereon, one of said members projecting beyond the other one and having a shoulder formed thereon with a gap between said shoulder and the adjacent end of the other member, a pin mounted on said tone arm and positioned to slide on one member and engage the shoulder on said other member to limit the oscillation of said .rm in one direction, said arm having means for lowering it through said gap upon the record when said pin contacts with said shoulde and said shoulder having an inclined suri face on one side in the path of said pin on its return stroke for lifting said spring member to allow said pin to return to its normal position.

7. The combination, with a phonograph turn table and its support, of a. tone arm mounted to slide vertically in said support and having a part to overhang said turn table,` and means cooperating with the rear portion of said tone arm for guiding said' overhanging part to the beginning of the groove in the record.

In witness whereof, I have hereunto set my hand this 18th day of May, 1917.

JOHN A.. SHEMAKER.

idVitnesses: GUS GUSTAFsoN, A. O. GUREN. 

